Responses
Nope. Cayena is the emperor and empress child while Rezef is known as an illegitimate kid of the emperor( meaning that his mom was not the empress). So they believed they had the same dad.
It is later revealed that Refez is actually the empress child but his dad is the duke( also ML's dad). Emperor knows about the affair and in order not to bring shame to the imperial family he himself spreads rumors about Refez being his illegitimate child. So they actually have the same mom.
Kinda complicated family

Wait the people who are shipping her with the brother, are they not rlly related?? or just is it insect shipp?